1. Field of the Invention
The present invention is related to a picture phone apparatus which checks whether picture data is valid or invalid and a picture phone system using the same.
2. Description of the Related Art
A picture phone apparatus has a function of communication with sound and a function of transmitting a picture of a user and a background picture to a counter station. In recent years, the picture phone apparatus is downsized as development of semiconductor technology and electronic technology. Recently, the models of a portable phone and PHS (Personal Handyphone System) telephone, which are provided with a camera, are becoming mainstream. In future, the picture phone apparatus seems to be widely used, allowing picture phone communication while it has the same functions and the same size as the present portable phone.
FIG. 1 shows the configuration of a conventional picture phone apparatus 300. The picture phone apparatus 300 can communicate by the radio wave through a public radio communication network (not shown) in real time. The picture phone apparatus 300 is composed of an imaging section 301, an image processing section 302, a multiplier 303, a display section 304, a communication control section 305, a separator 306, an audio processing section 307, a receiver 308, a transmitter 309 and an operation section 310.
The imaging section 301 includes a CCD camera and an image processor and is installed on an upper portion of a housing. The image processing section 302 compresses and converts picture data picked up by the imaging section 301 into transmission picture data. The multiplier 303 multiplexes the transmission picture data and transmission audio data, and outputs transmission data to the communication processing section 305. The display section 304 displays input data from the operation section 310, reception picture data and the picked-up picture data on a liquid crystal display (not shown). The communication processing section 305 controls communication with the public radio communication network. The separator 306 separates reception data into the reception picture data and reception sound data. The audio processing section 307 converts voice of a user supplied from the microphone 309 into the transmission sound data, and drives the speaker 308 to output the reception sound data from the separator 306. The operation section 310 includes alphanumeric keys which are used for input data and instructions.
As shown in FIG. 1, the picture data picked up by the imaging section 301 is encoded by the image processing section 302. The encoded picture data is sent to the multiplier 303 as the transmission picture data, and is multiplexed with the transmission audio data from the audio processing section 307 into the transmission data. The transmission data is transmitted to the public radio communication network by the communication processing section 305.
However, when the picture phone apparatus has a fold-type structure like a fold-type portable phone, an invalid picture such as a black picture is sent to the counter station when the picture phone apparatus is in a fold state or a lens cap is attached on a lens portion of the imaging section 301.
In order to solve this problem, the following technique is proposed in Japanese Laid Open Patent Application (JP-A-Heisei 10-98702). In this conventional example, a camera is provided to be popped up from the body of the picture phone apparatus. By operating the switch in conjunction with the popping of the camera, the transmission of the picked-up picture data to a counter station is prevented when the camera is stored, and is permitted when the camera is popped up. Also, in the transmission permission of the picture data, reception picture data is displayed. In the transmission prohibition of the picture data, the picture data picked-up by the camera is displayed only on the display section 304 of the picture phone apparatus, and is not transmitted to the counter station.
However, in the conventional picture phone apparatus, the picture data picked up by the camera is transmitted without checking whether the picture data is valid or invalid. For this reason, the picture data picked up by the camera under improper environment, e.g., in a dark place is transmitted to the counter station, which makes a user of the counter station uncomfortable.
In conjunction with the above description, a TV telephone is disclosed in Japanese Laid Open Patent Application (JP-A-Heisei 6-62395). In this conventional example, a storage unit stores picture data previously picked up by an imaging device. When a user of a receiver can not reply to a call at once, the picture data stored previously and speech data are synthesized into transmission data which is transmitted to a transmitter.
Also, an image processing apparatus is disclosed in Japanese Laid Open Patent Application (JP-P2000-287061A). In this conventional example, input bit map data is divided into blocks in accordance with block division positions indicating blocks of the whole final output image. It is checked whether each block is an invalid block which does not exist in the input bit map data. All valid blocks other than the invalid blocks are encoded.
Also, a communication terminal is disclosed in Japanese Laid Open Patent Application (JP-P2002-77840A). In this conventional communication terminal, reception picture data is generally displayed on a display unit. A storage unit stores a substitution picture data. Every time a user inputs a display switching instruction from a key input section during the communication, display picture data is alternately switched between the reception picture data and the substitution picture data.
Also, a mobile phone terminal is disclosed in Japanese Laid Open Patent Application (JP-P2002-125263A). In this conventional example, a control unit displays reception electric field intensity on a display section based on an electric field intensity signal from a radio communication section. During the picture communication, an electric field intensity display image is added to picture data picked up by an imaging section to be transmitted as transmission picture data. Also, when an alarm is generated from the control unit to indicate degradation of communication quality, an alarm image stored in a memory is added to the picture data picked up by the imaging section and transmitted or a substitution image stored in a storage is transmitted.
Also, an image processing apparatus is disclosed in Japanese Laid Open Patent Application (JP-P2002-247330A). In this conventional example, a valid image region and an invalid image region are separated from an image of a manuscript. A region determination image is generated based on the separation result to contain data of the valid image region and the invalid image region. An image processing section sets the invalid image region from a setting value by a user and the data of the valid image region and the invalid image region.
Also, a picture phone apparatus is disclosed in Japanese Laid Open Patent Application (JP-P2002-354436A). An imaging device picks up a user to produce picked-up picture data. EEPROM previously stores substitution picture data. A CG processing section selects one of the picked-up picture data and the substitution picture data in accordance with an instruction and the selected picture data is transmitted as transmission data.